"The changes caused by the inflammation are like a slow-growing cancer that goes undetected because they cause no symptoms."

The study found that inflammation from stress alters the structure of blood vessels and activates platelets to form, which increases clotting. As clots clump together plaque forms, ultimately leading to atherosclerosis, a narrowing or hardening of the arteries that could eventually cut off the flow of blood and cause a heart attack or stroke.

"Unfortunately, clots don't have boundaries," said Dr. Omer Iqbal, co-researcher at the Stritch School of Medicine. "They can dislodge and travel to the vessels of the heart and cause a heart attack, and they can also reach the brain and cause strokes."

In light of this new information, patients treated for depression should be routinely screened and monitored for heart disease and excessive stress.